Identifying and describing trajectories of alcohol use frequency and binge drinking frequency among those age 15-30 in a national cohort of U.S. adolescents: a group-based trajectory modeling approach.

Abstract

Analyzing long-term trajectories of alcohol use has the potential to strengthen policy and intervention priorities and timing. We identified and described trajectories of alcohol use and binge drinking frequency from mid-adolescence to early adulthood and measured the association of the role of early drinking initiation with trajectory membership. Longitudinal cohort study SETTING: United States PARTICIPANTS: The National Longitudinal Survey of Youth 1997 is a nationally representative cohort of youth age 12-16 at baseline. The analytic sample included individuals who participated in >2 annual interviews between age 15 and 30 (n=8,809). Participants self-reported the number of days in the past 30 days they: (1) drank alcohol and (2) binge drank [>5 drinks in one occasion]. We used group-based trajectory modeling to identify distinct trajectories from age 15-30 of past 30-day drinking and past 30-day binge drinking. Using multinomial logistic regression, we evaluated associations between early drinking initiation (≤14 years) and key demographics with trajectory membership. We identified 5 past 30-day drinking groups: late-escalating (16.0%), moderate-frequency (19.0%), high-frequency (11.1%), low-frequency (35.4%) and no/infrequent (18.4%). Early drinking initiation (versus later) was associated with higher odds of membership in the moderate (adjusted multinomial odds ratio [aMOR] = 4.32; 95% confidence interval [CI]: 3.65, 5.12) and high-frequency groups (aMOR = 4.17; 95%CI: 3.50, 4.97) than in the no/infrequent comparator trajectory. We identified 5 groups with distinct binge drinking frequency patterns: later escalating (9.9%), high-frequency (3.9%), low frequency (28.7%), earlier onset (9.5%), and no/infrequent (48.0%). Early initiation was associated with increased odds of membership in earlier onset and high-frequency groups compared with the no/infrequent group. For both outcomes additional differences in probability of group membership were identified by gender, racial identity, parental factors (religiosity, high school completion), and household characteristics (household size, income, and region of residence). Youth in the United States appear to follow heterogeneous drinking and binge drinking trajectories from adolescence into adulthood. These may include higher-use trajectories as well as trajectories with different escalation timing (e.g., earlier vs. later). Early initiation of drinking may increase risk of membership in higher- and earlier-use trajectory groups.